Preformed portable slab for use as a foundation or splash pad for industrial equipment

ABSTRACT

A portable precast slab that provides a foundation for a variety of industrial equipment that can be placed at locations where permanent foundations cannot be installed, or where an immediately usable foundation is needed. The slab is preferably about 4″-24″ in thickness, preferably at least about 6′ in length, and preferably at least about 6′ in width; multiple pieces may be used to form the slab. The slab may have attachment means incorporated in order to move the slab. If a bulk storage tank is placed upon the slab, preferably at least about 8 feet by about 8 feet area adjacent to the tank will be available for delivery of liquid cryogen. A method of making and using the slab is also contemplated, and the slab may also be used as a splash pad, and a pad for cryogenic pumps.

RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application No.60/503,961 filed on Sep. 19, 2003.

TECHNICAL FIELD

The present invention relates to portable pads or slabs, particularly toportable precast slabs for use as temporary, removable, or permanentfoundations for industrial equipment, bulk storage tanks, cryogenicliquid pumps, and the like, and related methods of making and using theslab. It is also suitable as a protective surface, for example as an offloading or splash pad for liquid oxygen, or liquid hydrogen, or othercryogenic liquids.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the invention.

FIG. 2 is a view of a reinforcing means of an embodiment of theinvention.

FIG. 3 is a side view of an attachment means of an embodiment of theinvention.

FIG. 4 is a side view of an attachment means of an embodiment of theinvention.

FIG. 5 is a top view of an embodiment of the invention.

FIG. 6 is a cross-sectional side view of an embodiment of the invention.

FIG. 7A is a cross-sectional side lengthwise view of an embodiment ofthe invention.

FIG. 7B is a cross-sectional side endwise view of an embodiment of theinvention.

FIG. 7C is a side view of an attachment means of an embodiment of theinvention.

FIG. 8 is a side view of an attachment means of an alternate embodimentof the invention.

DETAILED DESCRIPTION

For purposes of the description of this invention, the terms “upper,”“lower,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lower,”“side,” and other related terms shall be defined in relation toembodiments of the present invention as described herein and asillustrated in the accompanying figures. However, it is to be understoodthat the invention may assume various alternative structures andprocesses and still be within the scope and meaning of this disclosure.Further, it is to be understood that any specific dimensions and/orphysical characteristics related to the embodiments disclosed herein arecapable of modification and alteration while still remaining within thescope of the present invention and are, therefore, not intended to belimiting. The present invention relates to portable pads or slabscomprised of precast concrete or cement for use as temporary orremovable foundations for industrial equipment, bulk storage tanks,cryogenic liquid pumps, heat exchangers and associated equipment such asmanifolds, distillation columns, small buildings, and the like.

The use of portable or preformed structures that can readily betransferred to another location and/or can be used immediately afterdelivery and set up is very advantageous. In certain locations permanentfoundations cannot be installed and/or there is a need for a foundationthat can immediately be used. In other situations, rather thanpurchasing and installing permanent industrial equipment and components,a business owner may choose to lease portions of equipment for a certainduration, and such equipment may be best set up on a foundation, whichmay also be leased.

Certain suppliers will also lease expensive equipment such as a bulkstorage tanks to third parties that is used in conjunction with thepurchase of commodities such as liquid nitrogen and oxygen that are usedand replenished on a regular basis. Due to the limited duration of thesupply contracts and/or leases, it may be unfeasible for these businessowners to permanently install bulk storage tanks or other industrialequipment. In such a case, a foundation for the bulk storage tank orother industrial equipment is necessary, and a slab/pad that is portableand removable can be used in conjunction with the storage tank or otherindustrial equipment.

Additionally, business strategies as well as investment and accountingprinciples may necessitate portable equipment and components. Supplierresponse time can be also be shortened; by inventorying portable pads,equipment can be installed in less time.

Portable structures are also useful in locations such as easements andleased premises where permanent structures are forbidden and thestructures and equipment can be readily moved or relocated.

The invention contemplates a portable precast slab, with or withoutreinforcement, which is used as a foundation or splash pad. The slab/padhas a top surface, a bottom surface, a plurality of side surfaces, alength, a width, and a thickness, wherein the thickness varies and aweight bearing slab/pad is preferably at least about 6 inches to about24 inches or more, and may be up to about 48 inches thick. The thicknessof the pad is also important to prevent the slab from breaking apartduring lifting, loading, handling, use, and the like. Further, the slabis preferably at least about 6 feet in length, and may be up to about 20feet in length. Of course in other embodiments, slabs of similar squarefootage ranges may also be preferable. Similarly, the slab is preferablyat least about 6 feet in width, and may be up to about 12 feet in widthand even wider with the ultimate limitation being portability. In anembodiment, a slab of the dimensions of 10′×15′×16″ has been especiallyadvantageous for use as a foundation for cryogenic storage tanks. Inanother embodiment, slabs of the dimensions of 10′×15′ by 6″ thick,10′×15′ by 16″ thick, and 10′×15′ by 12″ thick have been found to beespecially desirous for use as a foundation for cryogenic storage tanks.The sixteen-inch thick slab that is 10′×15′ weighs approximately 29,250pounds.

The slab can be used as a foundation for a variety of industrialequipment and/or components. The slab may be used indoors or outdoors.The invention also contemplates a portable precast slab, with or withoutreinforcement, which is used as a splash pad for the offloading ofliquid cryogens, especially those that are flammable. Certain types ofsubstrates such as asphalt are flammable, and the dripping of certaincryogens such as oxygen onto asphalt can start a fire. In contrast, acement or concrete surface or substrate is not flammable. As such, thisinvention is also directed to slabs that are used as splash pads. Nospecial coating or films are required on the surface of the cement orconcrete in order for them to be used as splash pads.

Of course the slabs of this invention that are used as a foundation forindustrial equipment can also be used as splash pads, with or withoutholding industrial equipment. If the slab is to be used as only a splashpad and not as a weight bearing foundation, it does not require that theslab be of the same thickness as the slab that is used as a foundation.If for example the splash pad and foundation pad are to be placedadjacent to one another, slabs of the same thickness may be easier toinstall.

Further splash pads may be used alone or in conjunction with slabs thatare used as a foundation. Just like the slabs used as a foundation, thesplash pad has a top surface, a bottom surface, a plurality of sidesurfaces, a length, a width, and a thickness, wherein the thicknessvaries and is at least about 2 inches to about 48 inches, but is morepreferably at least about 2 inches to 6 inches in thickness. The splashpad is preferably a minimum of about 6 feet in length, and may be up toabout 20 feet in length or more.

In an embodiment, the splash pad is preferably a minimum of about 6 feetin width, and may be up to about 12 feet in width or more. In a furtherembodiment, a preferable splash pad is of a length of about 4 feet and awidth of about 8 feet. In another embodiment, the preferable splash padis of a length of about 8 feet and a width of about 8 feet. Of course,in other embodiments, splash pads of similar square footage may also beused. In all other respects, the splash pad can have the samecharacteristics and features of the foundation pad.

Further, the slabs/pads may have a means for attachment that allows theslab to be lifted and/or moved. The means for attachment may comprise avariety of apparatus, known to one skilled in the art such as at leastone lift pin or eye loop that is accessible from the top or sidesurfaces of the slab/pad, and that may or may not be recessed. The slabcould also be designed to be moved by a forklift, or alternatively maybe rigged without any specific attachment apparatus.

The slab/pad may also have a plurality of apertures that are cast intothe slab and that are visible from the top or side surfaces. Theapertures can be used for a variety of purposes such as to hold posts orto install fence posts therein.

Further, the slab/pad may interconnect or interface with another slab orpad that may be portable or permanent. This may include at least oneside surface that is shaped and/or sized to interconnect or interfacewith at least one side surface of another slab.

The slab/pad may have structural reinforcement. If so a variety of meansknown to one skilled in the art may be used to reinforce the concrete orcement.

Also, if the industrial equipment comprises a bulk oxygen or hydrogenstorage tank, preferably an at least 10 foot length by 10 foot widtharea on the top surface should be available for liquid oxygen deliveryafter the bulk storage tank is placed on the surface of the slab (i.e.,an offloading area for the working end of a tanker truck), or a splashpad may be placed adjacent to the foundation that has the same orsimilar width area. In an embodiment, if the slab is used for a bulkstorage tank, the slab should at least support a storage tank that isfilled with at least up to about 300 to about 3000 gallons of liquid ormore. Of course the pads may be used for tanks holding any other liquidsand having any other function. The pads have also been used for Argonand Nitrogen tanks.

Just like the slabs used as a foundation and splash pads, the pads thatare used for cryogenic liquid pumps or other industrial equipment have atop surface, a bottom surface, a plurality of side surfaces, a length, awidth, and a thickness, wherein the thickness varies and is at leastabout 4 inches to about 16 inches, but is more preferably at least about4 inches to about 10 inches in thickness. The pads used for cryogenicpumps are preferably a minimum of about 6 feet in length, at least about15 feet in length, and may be up to about 25 feet in length or more. Apad that is 8′8″×24′ by 8″ thick is one such size that has been used tohold a number of high-pressure cryogenic liquid pumps. Other pads ofvarious thickness and sizes are also contemplated for use to hold suchpumps.

Because the pad/slab structure must be portable and movable, it ispreferably light enough so that it can be lifted by equipment that iscommonly used to lift apparatuses, such as cranes and forklifts. Isshould also be weighted and sized so that it can be carried by a vehiclethat can safely travel on roads (with or without permits) or othercarriers such as boats.

This invention also contemplates a method of making and using a portableprecast reinforced cement or concrete slab.

As shown in FIG. 1, the precast slab/pad 2 has a top surface 4, aplurality of side surfaces 6, and a lower surface 8. A precast orpremolded slab means a slab, pad, foundation, or foundation componentthat is formed by casting cement into a form or mold at a differentlocation, prior to the time of actual use as a slab, pad, or foundationfor industrial equipment. The slab 2 also has a length 10, a width 12,and a thickness 14. Preferably, the slab has a thickness of at leastabout 6 inches to about 24 inches. The slabs that are used forfoundations are preferably comprised of reinforced cement or concrete 24and preferably have an attachment means 16, which allows the slab to belifted. Again, splash pads may also have such attachment means.

Attachment means are typically employed to lift and/or move the precastslab, pad, or foundation elements. The term attachment means refers to adevice or apparatus that can be incorporated into the slab that allowsthe slab to be moved or movable. For example, the means for attachmentmay essentially comprise lift pins, lift rings, lift bolts, and the likeand a combination thereof that are preferably are cast steel, or othersuch apparatus known or used by one skilled in the art for suchpurposes. The means for the attachment are preferably accessible fromthe top surface and/or side surface. The cable may be directly wrappedaround or looped through the attachment means, and for example inattachment means with a loop clips, hooks and the like that is attachedto cable can be inserted into or through the eye of the loop or aroundthe other types of attachment means. According to the present invention,the attachment means can also be used to secure other elements to theprecast slabs, including elements from the industrial equipment such astie down lines, ground lines, and the like used by one skilled in theart.

When installed, the top surface of the pad is horizontal with regard tothe ground/substrate, and the pad should be level or substantiallylevel. The term side surfaces refer to the edges or other regions of theslabs between the top and bottom surfaces, and where a vertical sidesurface may begin.

The slab should be heavy enough to provide a force great enough toresist sliding and movement during wind and seismic events as well asdisplacement, overturning and/or sliding of the equipment such as a bulkstorage tank during such events. Additional weight can also be added onsite, and consist of concrete, cement, or other weights, such as steel,lead, and water. Piers, gripping members, or other methods known to oneskilled in the art can be used in conjunction with the slab to resistsliding and overturning forces.

The slab should be sized such that it is capable of bearing the weightof the industrial equipment that sits upon the surface of the slab. Forexample, the design criteria of the preferred embodiment of the slab/padshould resist moving during wind or seismic events. For example, theslab/pad should preferably withstand wind speeds of about 100 mph, suchas that caused by a hurricane, and preferably should withstand seismiczone 4 conditions.

The slab/pad may comprise a unitary piece, or multiple pieces that areplaced adjacent to each other that touch or abut each other. A singlepiece slab/pad is preferable as it is easier and to set up. If a largeslab is required, such as one larger than 15 feet long by 10 feet wide,or, there are weight or transportation problems, a slab comprised ofmultiple pieces would be more desirable. Yet, there may be disadvantagesto using a slab/pad comprised of multiple pieces as is may be moredifficult to level multiple pieces, the assembly may be awkward, and thepieces may come apart. FIG. 1 shows a slab/pad comprised of multiplepieces with overlapping portions 9 in a stepped fashion that interfaceor interconnect. Alternatively, the slab/pad pieces can fit together ina variety of ways similar to puzzle pieces and may have a uniform depthat the edges with interlocking or interfitting projections and recesses,or may instead be square or rectangular pieces or other shaped piecesthat abut one another. In cases where multiple pieces are used to make aslab, pad, or foundation, the side surfaces are preferably the areawhere two pieces are joined together or placed adjacent to one anotherto form a pad or a slab. If so, at least on one side of the slab mayhave the ability to interconnect and/or interface other pads or slabs,portable or not, in order to create a larger surface. Should it becomenecessary to join the portable foundation to another, numerous joiningmeans are possible that can be used to connect one slab/pad to another.Several stakes may be used around the perimeter of the slab, or a framemay be installed around the perimeter of the slab to ensure that theslab pieces do not come apart. Alternatively, metal strap portions maybe placed around the joint areas. The slab/pad of FIG. 1 may also becomprised of a unitary piece, and would lack overlapping portions 9.

The slab/pad may be of any shape. Preferably, the slab used as afoundation will be shaped and sized so that there will be a perimeter ofslab left after the industrial equipment is placed on the slab. In someapplications, the slab may be circular, rectangular, square, or of othershapes that will fit into the area designated for the slab. In certainapplications, a certain slab area is desirable. For example, if the slabis used as foundation for a bulk storage tank, in an embodiment, atleast about an 8 foot length by an 8 foot width area on the top surfacethat is adjacent to the tank should be available for liquid oxygendelivery after the bulk storage tank is placed upon the pad or slab tocomply with industry requirements for liquid oxygen systems.

The slab/pad may be made a variety of ways that are known or used by oneskilled in the art. For example, concrete or cement can be poured into aform that that sits on a table, similar to wooden forms that are builtby contractors when foundations are constructed on-site, and the tablemust be designed to bear the weight of the filled form. The forms may bemade of plastic, wood, metal and other durable materials. The forms arepreferably steel as is the table. Once the concrete or cement is cured,which typically takes about 1-2 weeks, the sides of the form are removedleaving the slab/pad sitting on the steel table. When the concrete orcement dries, it pulls away from the table and the slab can be liftedoff the table. Other methods of molding as well as other types ofconcrete or cement may be used that are known or used by one skilled inthe art.

Adequate curing is essential to obtaining good quality concrete orcement and contributes to the durability and the wear resistance of theslab/pad. During the curing process, the concrete or cement should notdry out prematurely, but should retain moisture and gradually dry inorder to build up strength and gain durability and wear resistance. Theamount of time required to cure will depend upon the size and thicknessof the slab pieces as well as type of concrete or cement used. To slowthe drying, the slab/pad can be covered with plastic sheeting after themold is filled. Alternatively, a commercial curing compound may besprayed, brushed or rolled onto the surface of the concrete or cement.Also, for example, a water-reducing admixture such as one that meetsASTM C494 standards may also be mixed into the concrete or cement.Further, it is preferable that calcium chloride admixtures be avoided.

In an embodiment, the bottom of the slab/pad is concrete or cement. Ofcourse the plates or other apparatuses may also be attached or joined tothe bottom of the slab/pad. For example to increase friction between thesoil and the foundation or to grip the substrate, rebar or other metalor other materials that are rigid or semirigid could be could be moldedinto or otherwise attached the bottom of the concrete or cementpad/slab.

The cement that is used is preferably conventional cement, such asPortland cement, ASTM C 150, Type 1. The concrete that is used ispreferably conventional concrete, such as Portland cement, ASTM C 150,Type 1, which has an ultimate compressive strength of at least about2000 psi, and preferably to about 4000 psi. Of course, high strengthconcrete could also be used for at least a portion of the slab/pad. Themaximum water cement ratio is preferably about 0.45, with normal weightaggregate such as ASTM C33, with preferably no more than about 5% voidsin the concrete. Other aggregates, and criteria that are known or usedby one skilled in the art can also be used with respect to the choice ofconcrete or cement, aggregate, and percentage of voids in the concreteor cement. Depending upon the weight requirements, a portion oflightweight concrete or cement may also be used to form the slab/pad.

Varying densities of concrete or cement can also be used to increase thestability of the slab. For example, higher density concrete or cementmay be used in certain areas, such as the perimeter and edges, withlighter weight concrete or cement in locations such as the center. Alsothe slab/pad can be weighted such as at the edges to increase thestability of the slab/pad.

For durability, the concrete or cement is preferably reinforced. Forexample, a plurality of wires, rebars, rods, bars, plates, gravel,glass, glass fibers, or carbon fibers and a combination thereof can beused as a reinforcing means and are cast into the concrete or cement.Bars or rods 22, and rebars 26 such as those made from metal,fiberglass, or polymers or a combination thereof are preferably used toreinforce the concrete or cement slab. See FIG. 1. Rebars are the mostpreferable.

In an embodiment, the preferable rebar comply with ASTM A 615specification, and are grade 60 bars. Other standards known or used byone skilled in the art may also be used. If the bars are bent ordeformed, they are preferably bent or deformed while cold. Further, therebar or rods may also be formed into a support frame, and if desired,the means for attachment can be is removably or securably attached tothe support frame, rebar, or rods. Preferably, there is at least a2-inch to 3-inch thickness of concrete or cement that covers the rebars,bars, or rods, or plates. If glass, gravel, pebbles, broken stone, slag,or carbon fibers are chosen, they are preferably interspersed throughoutthe concrete or cement. See e.g. FIG. 8. The rebars or rods are placedin the form at the time of casting and act to strengthen the slab afterthe slab has cured.

Preferably, conventional rebar 26, such as ASTM A36 steel is used. Therebars may be arranged and spaced in a variety of ways. Preferably, therebars or rods are no more than about 3 feet apart, and are preferablyabout 12 inches to about 18 inches on center with respect to each other.Also, the rebars are preferably at least about #3 to about #10 rebarwhich is equivalent to about {fraction (3/8)} inch in diameter to about1¼ inches in diameter or more. Of course, rebar of a greater diametercan also be used. Further, the rebars may be parallel to one another andare preferably further criss-crossed. The rebar may be one layer thick,made into a 3 dimensional support frame, or instead two layers or moreof rebars can be used. For example, in an embodiment, the top rebars canbe #5 or ⅝ rebar in diameter, are criss-crossed, and are spaced about 16inches each way, while the bottom rebars are # 8 rebar or 1 inch indiameter and are criss-crossed with spacing about 12 inches to about 18inches on center from each rebar. Further, when two layers are used andthe rebar is criss-crossed, the rebar may be staggered and spaced suchthat rebar is present about every 6 inches to about every 8 inches.

If the slab/pad is such a length that extensions must be used to splicethe rebars to each other, the rebar is preferably overlapped at thespliced areas 27, such as in accordance with ACI 318, and preferably notless than 40 bar diameter, not less than about 1 inch to about 6 inchesof rebar in the lapped area. See e.g., FIG. 7A. Other criteria known orused by one skilled in the art may also suffice. The rebars or rods canalso be prestressed prior to molding, if desired. Prestressed refers toan object that is stretched and stressed prior to being molded in theslab.

Because the slab is portable, it preferably has a means of attachmentthat allows the slab to be moved and/or lifted, such as by a cable. Theterm cable refers to a line, strand, or chain or other such devicesknown or used by one skilled in the art that are which may be attachedor connected to the attachment means. A variety of apparatuses can beincorporated into the slab/pad that allows the slab/pad to be moved. Forexample, the means for attachment may comprise lift pins or lift ringsthat are preferably are cast steel, or other such apparatus known orused by one skilled in the art and are preferably accessible on and fromthe top or side surface. FIG. 3 is a cross-section of a lift pin that isremovably attachable to the slab. The pin 30 is steel and has anenlarged head 32 that allows cable 40 to be wrapped around the head, andhas a threaded end 34 that is insertable into corresponding threads 36in a metal housing 38. FIG. 3, shows the use of gravel 39 in a cementmatrix 40. Mortar could also be used. Of course the concrete may also becomprised of cement or mortar with pebbles, broken stone, or slag.

If the lift pin or other attachment means are accessible from the top,they are preferably perpendicular to the top surface of the slab. Ifthey are accessible from the side surface, they are preferablyperpendicular to the side surface(s). One such lifting pin is suppliedby Jenson Pre-Cast, and is an 8-ton lift pin. Preferably, the lift pinsdo not extend beyond the top surface of the concrete or cement. In anembodiment, attachments known as “knuckles” are attached to embeddedlift pins, and cables are attached to the “knuckles”.

Lift pins are also sold by other companies such as Conac, and come invarying strengths ranging from at least about 1 ton to about 26 tons.The required strength of the lift pin will depend upon weight,thickness, and size of the slab/pad or other such factors known or usedby one skilled in the art. FIG. 4 shows an attachment means that has alooped end 42 that protrudes from the top surface 4 of the slab 2 thatis embedded in the 24 slab. The eye loop allows for cable hooks to beinserted into the eye 44 of the loop. Preferably, the attachment meansdo not protrude from the surface, and are preferably recessed as in FIG.7C. The eyebolt may be threaded on one end and looped on the other end.FIGS. 7B and 7C shows a further embodiment of an attachment means thatis a pin 50 having an enlarged end 52 at both the surface of the slaband the end that is embedded into the slab. Also, the pin may be locatedin a recessed surface 5 of the slab so that it does not protrude abovethe top surface of the slab. This can be accomplished by placing a capon top of the pin to create the void at the top of the lifting pin. As afurther alternative, FIG. 8 shows an anchor bolt 54 with similar stressand weight bearing capabilities that has an enlarged end 58 that allowscables to be attached thereto. The anchor bolt may be embedded directlyinto the concrete or cement, such as at a depth of 12 inches 56.

If the attachment means such as a lift pin or bolt is not attached tothe rebar, it is preferable to embed the attachment means at least aboutone-half to about three-fourths of the width of the slab so that theattachment means will not pull out of the slab when the slab is liftedand/or lowered by attaching cables and the like to the attachment means.

All of the foregoing pins and attachment means are preferably placedwithin the form before the concrete or cement is poured into the form ormold and/or before the concrete or cement begins to dry. However, theattachment means may also be installed after the concrete or cement iscured. For example, a hole could be drilled through the pad and a rodwith a hook or eyelet with a bottom plate would be installed. Also theholes may be filled with epoxy after the attachment means is inserted.

The attachment means should be placed at a certain depth that precludesthem from pulling out of the concrete or cement, such as a depth of atleast about 4 to about 8 inches to about 12 inches to 14 inches or more.Of course the depth will be limited by the thickness of the slab. Theslab when used as a foundation is preferably at least about 1 foot thickto about 4 feet thick, depending upon the specific use. For example, ina slab that is 16 inches thick, the attachment means such as a pin ispreferably inserted to a depth of about 12 inches. Alternatively, theembedded end of the attachment means may be attached to the rebar, suchas by wrapping the embedded end of the attachment means around the rebaror otherwise securably or removably attaching the attachment means tothe rebar.

Depending upon the size and thickness of the slab, one or multiple meansfor attachment may be used. The number and spacing of the means forattachment should be apparent to one skilled in the art and will dependupon the strength of the attachment means as compared to the weight andsize of the slab so that stresses do not break the means for attachmentor cause the attachment means to pull out of the slab. For example, inFIG. 1, there is only one means for attachment 16 that is located at ornear the center of each slab 2. In contrast, the slab 2 of FIG. 5 has aplurality of separate means for attachment, and in an embodiment that is10 feet width by 15 feet length and 16 inches thick, three to four 8-tonlift pins are used. In any case, the means for attachment should bespaced and located so that the slab will be approximately level and easyto control when it is moved and placed upon the ground or othersubstrate.

The substrate 18 such as asphalt or ground upon which the slab is placedis preferably level prior to placing the slab on the substrate orground. See FIG. 7A. If the surface is not level, the surface willpreferably be leveled by a layer not more than about ½ inch depth toabout 1 foot depth of about {fraction (1/4)} inch to about {fraction(1/2)} inch, or more size angular aggregate below the pad, such as byAir Liquide America. Alternatively, the slab can be leveled after it isplaced upon the substrate or ground. For stability, it is preferablethat the slab not be installed on wet or soft soil. To ensure stability,the preferable allowable soil bearing pressure is at least about 1000psf (pounds per square foot). Also, preferably, there will be positivedrainage from the substrate.

After the slab is installed, there is no waiting for the slab to dry asit is already dried and cured prior to moving the slab. Therefore theslab can immediately be used as a foundation for industrial equipment 66such as a bulk storage tank 64 that can be placed directly upon the topsurface of the slab. See FIGS. 5, 7A. Any equipment can be placed uponthe slab as long as the slab meets the seismic load demands of theequipment, as determined by a structural engineer or other personskilled in the art.

Further, if the slab is used to support a storage tank that is placedupon the top surface, the additional weight from the stored liquid mustbe taken into account with respect to the size and thickness of theslab. For example, in an embodiment, for a slab that is 15 foot long by10 foot wide slab, and 16 inches thick, the storage tank can be filledwith up to about 1500 to about 3000 gallons of liquid oxygen. The weightof a storage tank with about 1500 gallons of liquid is about 28,100pounds, and a storage tank with about 3000 gallons of liquid is about47,000 pounds.

If it is desirable to install fencing around the perimeter of the slaband/or the industrial equipment, multiple apertures 70 which can holdfence posts can be incorporated, into the slab, such as by molding ordrilled into the molded slab. See FIG. 5. The apertures 70 may compriseblind holes that extend part way through the depth of the slab, or maycomprise holes that extend through the thickness of the slab. See FIGS.6, 7A. The holes may be of a diameter that is sufficient to receivefence posts. For example 4-inch diameter holes are used to receive3-inch diameter fence posts that are installed in the field. To createthe holes, 4-inch PVC capped pipe is placed in the mold/form before theconcrete or cement is poured. The PVC pipes create the multiple 4-inchdiameter voids. At a minimum, it is preferable to provide holes at leastin every corner of a rectangular or square slab. It may also beadvantageous to provide additional holes for the fence posts 7. Forexample, in a 15 foot long by 10 foot wide slab that holds a bulkstorage tank or vessel 64, it has been determined that at least nineholes should be molded into the slab.

The slab must preferably also adequately drain. In most circumstances, aflat slab will adequately drain. As an alternative, the slab may furtherhave a plurality of furrows 75 in the top surface of the slab to ensuredrainage of water from the slab. See FIG. 5. Furrows may be incorporatedby pressing a form into at least a portion of the top surface of theconcrete or cement, which has not hardened, or the furrows may be madeby other ways known to one skilled in the art. However, the furrowsshould be strategically located so that they do not cause the topsurface of the slab to be unlevel. Further, the concrete or cement maybe finished by a broom before it hardens so that the top surface is notslick.

In an embodiment, a vessel leg plate 62 of the vessel leg 66, such asfor a bulk storage tank, is also anchored to the slab, such as by ananchor bolt and epoxy. In an embodiment, a hole of a diameter ofapproximately ¾″ to about 1½″ that may extend as deep as the thicknessof the slab is drilled into the slab and/or vessel leg plate at thedesired position, then an epoxy pack is inserted and is ruptured by thebolt, mixing the epoxy portions together. A nut may then be installedupon the bolt to further secure the leg plate, which is accessiblethrough a portion of the vessel leg that is typically open. For example,Hilti supplies such epoxies and anchor bolts, and other such adhesivesand fasteners are also commercially available. Of course other suchmethods of securing the vessel leg and leg plate known to one skilled inthe art may also be used. In an embodiment, a layer of grout 60 may alsobe used between the vessel plate and the top surface 4 of the slab. Thelegs or portions of other types of industrial equipment may also besecured to the slab.

Again, a method of using a portable precast slab as a foundation forindustrial equipment is contemplated comprises: providing a portableprecast slab that has a top surface, a plurality of side surfaces, alower surface, a length, a width, and a thickness. During use, the lowersurface of the slab is placed on ground, and the level of the slab ischecked and/or the slab is leveled. Next, at least one piece ofindustrial equipment can be placed on the top surface of the slab.

The method also contemplates the step of casting reinforcing means intothe concrete or cement, wherein the reinforcing means is selected fromthe group consisting essentially of wires, rebars, rods, bars, plates,gravel, glass, or carbon fibers or a combination thereof.

The method also comprises the step of providing means for moving orlifting the slab that is accessible from the top surface or side surfaceof the slab. The means for lifting or moving may be selected from thegroup consisting essentially of at least one lift pin, at least one liftring, at least one lift bolt, an anchor bolt, and a combination thereof.The means for attachment may be securably attached or removablyattachable. Also, the method further comprises the step of attaching acable to the lifting means and lifting the slab.

In this method, for example, the industrial equipment may comprise abulk storage tank. If so, it may be desirable to provide a slab that hasat least a 10-foot length by a 10-foot width area on the top surfaceadjacent to the tank that is available for liquid oxygen delivery afterthe bulk storage tank is placed on the top surface of the slab.

The slab may comprise multiple pieces and the pieces may be placedadjacent to each other to form the slab.

Further in this method, fencing may be installed around the perimeter ofthe slab and/or the industrial equipment.

Also this method may further comprise the step of using at least aportion of the slab as a splash pad.

A method is also contemplated for making a precast reinforced slab thatis used as a foundation for at least one bulk storage tank or systemthat comprises providing a mold or form, at least partially filling themold with concrete and placing at least one rebar or rod within theconcrete or cement to reinforce the concrete or cement, wherein at leastone rebar or rod has at least one lift pin or means for attachment thatis integral with or removably attached to the at least one rebar. Next,the rebars or rods are covered with concrete or cement.

Then, the concrete or cement is allowed to dry and/or cure, therebyforming a slab/pad, wherein the slab/pad has a top surface, a bottomsurface, a plurality of side surfaces, a length, a width, and athickness. The slab is removed from the form when the slab is at leastpartially dried. In this method, there may also be a plurality ofapertures that are cast into the slab that are visible from the topsurface. The apertures have a variety of uses and for example can beused to install fence posts therein.

In this method, the mold or form provides at least one side surfaceshaped so that the slab is capable of interconnecting or interfacingwith at least one side surface of another slab.

Further, in this method, a plurality of rebars or rods are used as areinforcing means, and the rebar is placed parallel to one anotherand/or in a criss-cross fashion.

Further, where a plurality of rebars or rods are used as a reinforcingmeans, the rebars or rods are arranged to form a three-dimensionalsupport structure that is cast into the concrete or cement. Also in thismethod, the rebar or rod may be prestressed prior to molding.

In this method, the slab is dried and/or cured prior to use.

In this method, at least a portion of lightweight concrete or cement orother materials designed to reduce the weight of the preformed pad maybe used to form the slab.

Further, as part of this method, a plurality of furrows may be made inthe top surface of the slab to ensure drainage of water from the topsurface of the slab.

Additionally, if the pad is used as a foundation for a bulk storagetank, the slab preferably has at least a 10-foot width by 10-foot lengtharea on the top surface that will be available for liquid oxygendelivery after the bulk storage tank is placed on the top surface of theslab.

It is noted that the methods and embodiment of apparatus describedherein in detail for exemplary purposes is of course subject to manydifferent variations in structure, design, application and methodology.Because many varying and different embodiments may be made within thescope of the inventive concept(s) herein taught, and because manymodifications may be made in the embodiment herein detailed inaccordance with the descriptive requirements of the law, it is to beunderstood that the details herein are to be interpreted as illustrativeand not in a limiting sense.

Further, it will be understood that many additional changes in thedetails, materials, steps and arrangement of parts, which have beenherein described and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims. Thus,the present invention is not intended to be limited to the specificembodiments in the examples given above and/or the attached drawings.

1. A method of using a portable precast slab as a foundation forindustrial equipment, comprising: providing a portable precast slab thathas a top surface, a plurality of side surfaces, a lower surface, alength of at least about 6 feet, a width of at least about 6 feet, and athickness of at least about 4 inches, wherein said slab is comprised ofconcrete or cement; placing the lower surface of the slab on ground;leveling the slab and/or checking the level of the slab; and placing atleast one piece of industrial equipment on the top surface of the slab.2. The method of claim 1, further comprising the step of castingreinforcing means into the concrete or cement.
 3. The method of claim 1,further comprising the step of providing a means for attachment, whereinsaid means is accessible from the top surface or side surface of saidslab.
 4. The method of claim 3, wherein said means for attachment isselected from the group consisting essentially of at least one lift pin,at least one lift ring, at least one lift bolt, an anchor bolt, or acombination thereof.
 5. The method of claim 3, further comprising thesteps of: attaching a cable to said means for attachment; and moving theslab.
 6. The method of claim 1, wherein the industrial equipmentcomprises a bulk storage tank.
 7. The method of claim 6, furthercomprising the step of anchoring at least one leg of the bulk storagetank to the slab.
 8. The method of claim 1, further comprising the stepof installing fencing around the perimeter of the slab and/or theindustrial equipment.
 9. The method of claim 1, further comprising thesteps of: using a slab that comprises multiple pieces; and placing saidpieces adjacent to each other to form the slab.
 10. The method of claim6, further comprising the step of providing a slab having at least aboutan 8 foot length by about an 8 foot width area on the top surfaceadjacent to said tank that is available for liquid oxygen delivery aftersaid bulk storage tank is placed on the top surface of said slab. 11.The method of claim 1, further comprising the step of using at least aportion of the slab as a splash pad.
 12. The method of claim 1, whereinthe industrial equipment comprises at least one cryogenic liquid pump.13. The method of claim 12, wherein the pad is at least about 6 feet toabout 10 feet in width, about 15 feet to about 30 feet in length, andabout 4 inches to about 10 inches in thickness.
 14. The method of claim12, wherein the pad is about 8′8″ in width by about 24′ in length, andabout 8″ in thickness.
 15. A portable precast reinforced slab used as afoundation for industrial equipment, comprising: a precast or premoldedslab comprised of concrete or cement, wherein the slab has a topsurface, a bottom surface, a plurality of side surfaces, a length, awidth, and a thickness; wherein said thickness is at least about 6inches to about 24 inches, wherein said length is at least about 6 feet,and wherein said width is at least about 6 feet; wherein the concrete orcement is reinforced by reinforcing means; and wherein during use theslab is level or substantially level and is used as a foundation forindustrial equipment.
 16. The slab of claim 15, further comprising meansof attachment, wherein said means for attachment is selected from thegroup consisting essentially of at least one lift pin, at least one liftring, at least one lift-bolt, at least one anchor bolt, and acombination thereof.
 17. The slab of claim 15, having a plurality ofapertures cast into said slab that are visible from the top or sidesurfaces, wherein said apertures can be used to install fence poststherein.
 18. The slab of claim 15, having at least one side surface thatis shaped and/or sized to interconnect or interface with at least oneside surface of another slab.
 19. The slab of claim 15, wherein aplurality of rebars or rods are used as the reinforcing means and arecast into the concrete or cement, and wherein said rebars or rods areplaced parallel to one another and/or in a criss-cross fashion.
 20. Theslab of claim 15, wherein the industrial equipment comprises a bulkstorage tank.
 21. The slab of claim 20, having at least about an 8 footlength by an about 8 foot width area on the top surface adjacent to saidtank available for liquid oxygen delivery after the tank is placed uponsaid slab.
 22. The slab of claim 19, wherein said rebars or rods areformed into a support frame and wherein said means for attachment isremovably or securably attached to said support frame.
 23. A method ofmaking a precast slab that is used as a foundation for at least one bulkstorage tank, comprising: providing a form; at least partially fillingthe form with concrete or cement; placing at least one means forattachment into the concrete or cement; filling the form with concreteor cement; allowing the concrete or cement to dry and/or cure, therebyforming a slab, wherein the slab has a top surface, a bottom surface, aplurality of side surfaces, a length, a width, and a thickness, andwherein said slab is at least about 6 inches thick to about 24 inchesthick; and removing the slab from the form when the concrete or cementis at least partially dried.
 24. The method of claim 23, furthercomprising the steps of: casting a plurality of apertures into said slabthat are visible from the top surface; placing the slab at an industrialsite; and installing fence posts into the apertures.
 25. The method ofclaim 23, further comprising the steps of: constructing a slab thatcomprises more than one piece; and providing at least one side surfacein said pieces that are shaped so that said pieces are capable ofinterconnecting or interfacing to form a slab.
 26. The method of claim23, further comprising the step of: casting reinforcing means into theslab.
 27. The method of claim 26, further comprising the steps of: usinga plurality of rebars or rods as the reinforcing means in the slab; andplacing said rebars or rods placed parallel to one another and/or in acriss-cross fashion.
 28. The method of claim 26, wherein said rebars orrods are arranged to form a three-dimensional support structure.
 29. Themethod of claim 26, wherein the rebars or rods are prestressed prior tomolding.
 30. The method of claim 23, wherein slab is dried and/or curedprior to use.
 31. The method of claim 23, further comprising the step ofusing concrete or cement of different densities to form said slab. 32.The method of claim 26, further comprising the step of making aplurality of furrows in the top surface of said slab to ensure drainageof water from the top surface of said slab.
 33. A method of using aportable precast slab for use as a splash pad for cryogenic liquids,comprising: providing a portable precast slab comprised of concrete orcement, wherein said slab has a top surface, a plurality of sidesurfaces, a lower surface, a length, a width, and a thickness, whereinsaid length is at least about 6 feet, wherein said width is at leastabout 6 feet, and wherein said thickness is at least about 2 inches;placing the lower surface of the slab on ground; offloading liquidcryogens over or adjacent to said slab; and using the top surface of theslab to catch at least a portion of the liquid cryogens that splash fromthe offloading of said cryogens.
 34. The method of claim 33, furthercomprising the step of casting reinforcing means into the concrete orcement.
 35. The method of claim 33, further comprising the step ofproviding a means for attachment, wherein said means is accessible fromthe top or side surface of said slab.
 36. The method of claim 35,wherein said means for attachment is selected from the group consistingessentially of at least one lift pin, at least one lift ring, at leastone lift bolt, an anchor bolt, and a combination thereof.
 37. The methodof claim 35, further comprising the steps of: attaching a cable to saidmeans for attachment; and moving the slab.
 38. The method of claim 33,further comprising the steps of: using a slab that comprises multiplepieces; and placing said pieces adjacent to each other to form the slab.39. A method for providing a portable precast foundation for a bulkstorage tank, comprising: obtaining a portable precast slab that has atop surface, a plurality of side surfaces, a lower surface, a length, awidth, and a thickness, wherein said length is between about 6 feet toabout 20 feet, wherein said width is about 6 feet to about 12 feet, andwherein said thickness is about 6 inches to about 24 inches; whereinsaid slab is comprised of reinforced concrete or cement and wherein saidconcrete or cement is reinforced by means selected from the groupconsisting essentially of wire, rebar, rods, or a combination thereof;moving said slab to its desired location; placing the lower surface ofthe slab on substrate; leveling the slab and/or checking the level ofthe slab; and placing a bulk storage tank upon the top surface of theslab.
 40. The method of claim 39, further comprising the step of castinga means for attachment into said concrete or cement, wherein said meansis accessible from the top or side surface of said slab, and whereinsaid means is used to move said slab.
 41. The method of claim 40,wherein said means for attachment is selected from the group consistingessentially of at least one lift pin, at least one lift ring, at leastone lift bolt, at least anchor bolt, and a combination thereof.
 42. Themethod of claim 40, further comprising the step of anchoring at least apart of the bulk storage tank to the slab.
 43. The method of claim 40,further comprising the steps of: casting apertures into said concrete orcement; installing fence posts into said apertures after the slab isplaced upon said ground; attaching fencing to said fence posts; andinstalling fencing around the perimeter of the slab and/or the tank. 44.The method of claim 40, further comprising the step using at least aportion of the slab as a splash pad.
 45. The method of claim 39, whereinthe width of said slab is about 10 feet.
 46. The method of claim 39,wherein the length of said slab is about 12 feet.
 47. The method ofclaim 39, wherein the slab is between about 6 inches and 16 inches inthickness.
 48. The method of claim 39, wherein the slab is about 10′ inwidth, about 15′ feet in length, and either about 6″ in thickness orabout 12″ in thickness.
 49. The method of claim 39, wherein the slab isabout 10′ in width, about 15′ feet in length, and about 16″ inthickness.